HISTORY OF FLIGHT On September 3, 2015, about 0917 Pacific daylight time, a Piper PA-28-161 airplane, N8441B, impacted a residential area in Santee, California, shortly after takeoff from Gillespie Field Airport (SEE), San Diego/El Cajon, California. The flight instructor and student pilot were fatally injured, and the airplane was substantially damaged. The instructional flight was operated by Golden State Flying Club, El Cajon, California, under the provisions of 14 Code of Federal Regulations Part 91. Visual meteorological conditions prevailed, and no flight plan had been filed for the local flight. According to the Federal Aviation Administration (FAA), air traffic tower personnel at SEE reported that the airplane had been conducting touch-and-go takeoffs and landings on runway 27R. The controller stated that after completion of the second touch-and-go, he expected that the airplane would turn right onto the crosswind leg of the traffic pattern. However, the airplane turned left and descended rapidly toward terrain west of the field. There were no mayday calls received from the accident airplane. A witness in a vehicle watched the airplane take off and follow a normal climb path. Then he saw the left-wing dip, which initially he thought was a normal traffic pattern turn. He realized that the left wing continued to dip "more severely than normal," and the left bank increased as the airplane flew toward an open field at the west end of the runway. As the airplane continued in a tight left turn, it lost altitude "very quickly," and subsequently impacted the ground. A witness located near the accident site reported that he heard the airplane's engine "shut off," and stated that it sounded as if the engine was "trying to restart." The airplane then impacted three vehicles, and came to rest inverted in a driveway; a postaccident fire ensued. PERSONNEL INFORMATION AIRCRAFT INFORMATION According to the engine logbooks, the engine was overhauled by Ly-Con Rebuilding company in Visalia, California, and installed on the accident airplane June 25, 2014. At that time, new Slick Champion Aerospace magnetos were installed. A review of the flight schools squawk sheets revealed no identified issues with the magnetos. WRECKAGE AND IMPACT INFORMATION The entirety of the airplane was located at the accident site; and sustained thermal damage during a postcrash fire. The left wing had separated from the airplane, and came to rest on top of the right wing. The fuselage and cockpit area sustained ground impact damage. The flap handle was in between the zero detent and the 10° detent. The ignition switch was found with the key broken inside and the switch was positioned to the "left mag." The fuel selector was positioned to the right fuel tank position. The left-wing fuel tank was breached, but contained 13 gallons of blue-colored liquid consistent with 100-LL aviation fuel. About 23 gallons of fuel was retrieved from the right wing. The engine remained attached to its mount; the mount was separated from the firewall. The engine assembly came to rest adjacent to the airplane. Several of the rear case accessories separated from their respective mounting pads. The left magneto separated from its mounting pad and was not located. The propeller remained attached to the engine crankshaft with the spinner exhibiting aft crush damage. One blade was bent forward and the other blade was bent aft. Both propeller blades had minor leading edge and chordwise damage, and remained intact. MEDICAL AND PATHOLOGICAL INFORMATION Flight Instructor The County of San Diego, Office of the Medical Examiner, San Diego, California, performed the autopsy of the flight instructor. The cause of death was reported as multiple blunt force injuries, with a contributing cause of traumatic asphyxia. The manner of death was listed as an accident. The FAA's Bioaeronautical Sciences Research Laboratory, Oklahoma City, Oklahoma performed toxicology testing on submitted specimens from the pilot. The test results yielded negative findings for carbon monoxide, cyanide, ethanol, and drugs of abuse. Student Pilot The County of San Diego, Office of the Medical Examiner performed the autopsy of the student pilot. The cause of death was reported as blunt force head injuries. The manner of death was listed as an accident. The FAA's Bioaeronautical Sciences Research Laboratory performed toxicology testing on submitted specimens from the student pilot. The test results yielded negative findings for carbon monoxide, cyanide, and ethanol. The results for tested drugs of abuse were positive for the following: Anhydroecgonine Methyl Ester detected in urine Anhydroecgonine Methyl Ester not detected in blood 0.101 (ug/ml, ug/g) Benzoylecgonine detected in urine Benzoylecgonine not detected in blood Ecgonine Methyl Ester detected in urine Ecgonine Methyl Ester detected in blood 2.047 (ug/ml, ug/g) Phentermine detected in urine 0.1 (ug/ml, ug/g) Phentermine detected in blood (lliac) 0.099 (ug/ml, ug/g) Phentermine detected in serum According to the FAA, Benzoylecgonine is the predominate metabolite of cocaine, and is used as an indicator of cocaine use. Anhydroecgonine methyl ester is a unique pyrolysis product that is formed when cocaine is smoked, and is a possible indicator of "crack cocaine" use. Ecognine methyl ester is an inactive minor metabolite of cocaine. Phentermine is a schedule IV, short-term use, prescription appetite suppressant. The FAA reported that phentermine is not an acceptable medication for use while performing airman duties. The toxicological findings indicated that although the student had used cocaine hours to a few days before the accident, there was no parent (active) drug detected. TEST AND RESEARCH INFORMATION The examination of the airframe revealed no preimpact failures were noted with any flight control surface or flight control system components. The engine was manually rotated using a drive tool at the vacuum pump drive. The engine rotated freely, and compression was produced in all four cylinders, which also established valve and gear train continuity. The right magneto (non-impulse coupled magneto) remained attached to the engine at its mounting pad. The magneto was removed and visually examined. During manual rotation of the magneto drive, internal friction was detected and audible grinding was heard. Further examination of the right magneto revealed no obvious signs of damage. Maintenance personnel were not able to manually rotate the magneto; however, the top gear rotated freely. When the magneto was opened, the distributor gear electrode was not seated properly, and the distributor drive gear was stuck inside the magneto. Once disassembled, the cam follower appeared to be in good condition and the points appeared to be brand new. The rotor drive lower ball bearing was frozen; however, the upper bearing rotated freely with no binding. There was rust present in the rotor drive, but it could not be determined whether it was present before the accident or formed after the accident. The internal components were all in good condition and each individual test of the capacitor, electrodes, and coil were within manufacturer specifications; and the components were in good condition.